AN OPTIMAL-MODEL TO SIMULATE GROWTH OF MICROORGANISM ON A DISSACHARIDE

The growth of micro-organisms on disaccharides, like lactose, is highl y dependant on the enzymic degradation rate of these disaccharides. Af ter degradation of lactose, growth essentially takes place on a mixtur e of glucose and galactose present in the fermentation broth. The cata bolic repression of glucose on the synthesis of P-galactosidase and th e uptake of galactose controls growth. This is demonstrated by batch g rowth experiments on the growth of Lactobacillus bulgaricus on lactose . An optimal model is developed to simulate growth on lactose and on m ixtures of glucose, lactose and galactose. The model is able to predic t the effect of a glucose pulse during growth on lactose. (C) 1998 Els evier Science Ltd. All rights reserved.